20" LCD Monitors Roundup. Part IV. Page 11

With this article I’m willing to introduce to you a few new models of 20" LCD monitors from different brands. You’ll find here monitors for work and for the home, affordable and not quite, with new widescreen matrixes as well as with the classic aspect ratio of 4:3. We will talk about 13 solutions from Asus, BenQ, Dell, HP, LG, NEC, Philips, Samsung and Viewsonic.

The monitor’s got 50% brightness by default. Contrast is again not regulated when the monitor is connected via DVI. That’s why I didn’t perform my tests at our three traditional reference points (100 nits, default settings, maximum settings) but limited myself to the minimum and maximum levels of brightness.

The brightness is regulated by means of pulse-width modulation of the backlight lamps at a frequency of 158Hz.

Default settings

The gamma curves look perfect at the default brightness setting (50%). There are no problems with the reproduction of darks or lights.

Minimal brightness

But when the brightness is reduced to zero, the monitor loses details in darks. The diagram above shows that the red and green curves lie on the X-axis for about 10-15% of dark halftones. This means that these halftones are all displayed by the monitor as pure black. It also means that the monitor actually uses a mixed regulation of the brightness, with the lamps and the matrix both. So, if you care about having all the range of halftones displayed properly, you should reduce the monitor’s brightness setting cautiously and use your graphics card settings for more regulation.

Strangely enough, the color temperature modes did not work on our sample of the monitor. This must have something to do with the firmware, but I want to make it clear that I tested an off-the-shelf product, not an engineering sample. The color temperature settings were available for DVI connection, but my choosing them had no effect, except for the manual setup in the Custom mode.

The single mode the monitor could produce was set up quite well, though. The difference between the temperatures of different grays wasn’t higher than 500K. It is a good result.

The monitor’s color gamut is standard. It is somewhat larger than the sRGB space in the area of greens but smaller than it in reds. This is in fact the typical color gamut of most modern LCD monitors except for a few models that have backlight lamps with improved phosphors and boast a color space that is considerably larger than sRGB.

This monitor is based on an S-IPS matrix with Response Time Compensation although its specs declare a response time of 16 milliseconds as measured according to the ISO 13406-2 standard. The response time average is 6.0 milliseconds and there are few transitions that differ much from this value. Thus, the 2007WFP has a very fast matrix that is going to suit well for both movies and games.

Alas, the RTC mechanism has its errors: 9.2% on average and 42.9% at the maximum. Almost each transition is performed with an error, particularly the transitions from black into grays which are the most conspicuous. RTC-provoked artifacts won’t be too annoying at work or in games (I consider an RTC error level of 10% as the acceptable maximum and the 2007WFP meets this requirement), yet are going to be visible for the user.

The monitor’s contrast ratio is over 300:1 at the maximum, which is an average result by today’s standards. Well, S-IPS matrixes have never had record-breaking contrast ratios, being inferior to S-PVA matrixes in this respect as we can see now comparing the 2007WFP and the 2007FP.

So, Dell has done a good job on this product. The 2007WFP is a good choice not only for those who are not satisfied with the small viewing angles of TN matrixes, but also for people who need an accurate reproduction of colors, yet can’t afford a NEC 2090UXi, for example. Besides color reproduction and viewing angles, I want to mention the fast matrix, good ergonomics, and appealing appearance. On the downside is the noticeably high level of RTC errors, malfunctioning option of the color temperature selection (this seems to be a problem of the particular firmware, but make sure at the shop that the sample you are going to buy is free from it), and the loss of darks at low values of brightness.

It’s hard to tell which matrix type is better, S-IPS or S-PVA. The former offers somewhat larger viewing angles (and, consequently, a somewhat better reproduction of colors) and a better response time, but the latter features a higher contrast ratio and a smaller RTC error. On the other hand, these differences are going to be insignificant for a majority of users.